A simulation studying the effects of solvation on one of the identical subunits of the dimeric HIV-1 protease was reported previously. Final revision of the manuscript reporting the results was accomplished, and the manuscript published during the reporting period. The "flap" region of the protease monomer was found be surprisingly rigid, although mobile. Work is continuing to compare other aspects of the simulation, especially bond vector reorientation, with recent NMR experiments performed in BRB, NIDR, NIH.